Optical spectroscopy and energy-filtered transmission electron microscopy of surface plasmons in core-shell nanoparticles

Antibacterial core–shell nanoparticles based on poly(hexamethylene guanidine hydrochloride) (PHMG) oligomers and poly(acrylic acid) (PAA) networks are efficiently fabricated via a facile one-step co-polymerization of acrylic acid and N,N′-methylenebisacrylamide on PHMG templates in aqueous solution. Dynamic light scattering, Fourier-transform infrared spectroscopy, and transmission electron microscopy observations were used to characterize the size, morphology, and structure of the nanoparticles, as well as the interactions between the components. Also, the stability of the nanoparticle dispersion against storage, pH value, salt, and temperature was investigated. The results show that the crosslinked PAA/PHMG nanoparticles are stabilized by electrostatic interactions. The core–shell structure of the nanoparticles was confirmed by transmission electron microscopy observation. The size of the nanoparticles increases substantially with extension of storage or with increase of the salt concentration. The nanoparticle dispersion is stable in a pH range of 2.0–4.0. The size change of the nanoparticles with pH of the medium is parabolic, and the minimum size is reached at pH 3.0. A rise of temperature leads to a slight and recoverable size increase of the nanoparticles. Antibacterial efficiency was evaluated quantitatively against Escherichia coli and Staphylococcus aureus by the plating method according to Standard JC/T 897–2002. The antibacterial activity against these two bacteria are both above 99.0 % at a nanoparticle concentration of 5 mg mL–1. This makes the nanoparticle dispersion a good candidate for the application of antibacterial water-based coatings and textiles coating.

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Synthesis and Characterization of WO3/S Core/Shell Nanoparticles by Thermal Evaporation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.602-603.51 ◽

2014 ◽

Vol 602-603 ◽

pp. 51-54 ◽

Cited By ~ 3

Author(s):

Jing Wen Qian ◽

Zhi Jian Peng ◽

Dian Zhong Wu ◽

Xiu Li Fu

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Large Scale ◽

Thermal Evaporation ◽

Nano Particles ◽

Core Shell ◽

Shell Nanoparticles ◽

Transmission Electron ◽

Composition And Structure ◽

Core Shell Nanoparticles

WO3 has been widely applied in many fields such as electrochromic window, photocatalyst, and gas-senor. In this paper, WO3/S core/shell nanoparticles were synthesized in high density and large scale on silicon substrates via simple thermal evaporation of WO3 and S powders at 950 °C in a tube furnace. The morphology, composition and structure of the nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy. The results indicate that the nano-particles have a uniform morphology with a diameter in the range of 150-250 nm and well crystalline structure. The growth mechanism of the nanoparticles was also proposed.

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Preparation and Characterization of Nickel(Ni)-Silver(Ag) Core-Shell Nanoparticles for Conductive Pastes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.531.211 ◽

2012 ◽

Vol 531 ◽

pp. 211-214 ◽

Cited By ~ 3

Author(s):

Jun Jie Jing ◽

Ji Min Xie ◽

Hui Ru Qin ◽

Wen Hua Li ◽

Ming Mei Zhang

Keyword(s):

Electron Microscopy ◽

Inductively Coupled Plasma ◽

Water Solution ◽

Average Diameter ◽

Core Shell ◽

Ni Nanoparticles ◽

Shell Nanoparticles ◽

Inductively Coupled ◽

Transmission Electron ◽

Core Shell Nanoparticles

Nickel(Ni)-silver(Ag) core-shell nanoparticles with different shell thickness were synthesized with Ni nanoparticles by liquid phase reduction technique form water solution. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and inductively coupled plasma spectroscopy (ICP). The results showed that the Ni nanoparticles are in sphere shape and the average diameter is 104nm , the nickel(Ni)-silver(Ag) core-shell nanoparticles has good crystallinity and the thinkness of Ag nanoshells could be effectively controlled by changing the concentration of silver nitrate. The product can be used for nickel-based conductive paste preparation because of the surface character of Ag and the magnetic property of Ni

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In situ TEM observation of Au–Cu2O core–shell growth in liquids

Nanoscale ◽

10.1039/c9nr00972h ◽

2019 ◽

Vol 11 (21) ◽

pp. 10486-10492 ◽

Cited By ~ 5

Author(s):

Fu-Chun Chen ◽

Jui-Yuan Chen ◽

Ya-Hsuan Lin ◽

Ming-Yu Kuo ◽

Yung-Jung Hsu ◽

...

Keyword(s):

Electron Microscopy ◽

Shell Growth ◽

Core Shell ◽

In Situ Tem ◽

Shell Nanoparticles ◽

Transmission Electron ◽

Liquid Cell ◽

Different Shapes ◽

Core Shell Nanoparticles

The formation of different shapes Au–Cu2O core–shell nanoparticles was investigated by in situ liquid cell transmission electron microscopy (LCTEM).

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Synthesis, Characterization and Dye Removal Behavior of Core–Shell–Shell Fe3O4/Ag/Polyoxometalates Ternary Nanocomposites

Nanomaterials ◽

10.3390/nano9091255 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1255 ◽

Cited By ~ 3

Author(s):

Shixia Zhan ◽

Chunyan Li ◽

Heyun Tian ◽

Chenguang Ma ◽

Hongling Liu ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Magnetic Properties ◽

Removal Efficiency ◽

Dye Removal ◽

Physical Property Measurement System ◽

Core Shell ◽

Shell Nanoparticles ◽

Transmission Electron ◽

Vis Spectroscopy

The ternary nanocomposites Fe3O4/Ag/polyoxometalates (Fe3O4/Ag/POMs) with core–shell–core nanostructure were synthesized by coating [Cu(C6H6N2O)2(H2O)]H2[Cu(C6H6N2O)2(P2Mo5O23)]·4H2O polyoxometalates on the surface of Fe3O4/Ag (core–shell) nanoparticles. The transmission electron microscopy/high resolution transmission electron microscopy (HR-TEM) and X-ray powder diffraction (XRD) analyses show that the Fe3O4/Ag/POMs ternary nanocomposites reveal a core–shell–core nanostructure, good dispersibility, and high crystallinity. The vibrating sample magnetometer (VSM) and physical property measurement system (PPMS) demonstrated the good magnetic properties and superparamagnetic behavior of the nanocomposites at 300 K. The UV–vis spectroscopy displayed the broadband absorption of the Fe3O4/Ag/POMs with the maximum surface plasmon resonance of Ag nanostructure around 420 nm. The dye removal capacity of Fe3O4/Ag/POMs was investigated using methylene blue (MB) as a probe. Through adsorption and photocatalysis, the nanocomposites could quickly remove MB with a removal efficiency of 98.7% under the irradiation of visible light at room temperature. The removal efficiency was still as high as 97.5% even after six runs by magnetic separation of photocatalytic adsorbents after processing, indicating the reusability and high stability of the nanocomposites. These Fe3O4/Ag/POMs photocatalytic adsorbents with magnetic properties will hopefully become a functional material for wastewater treatment in the future.

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